The disclosure relates generally to hot gas path components having cooling passageways cast therein, for use in turbomachines such as gas turbines. More particularly, the disclosure relates to an active sealing member for sealing cast-in holes in the cooling passageway walls.
Components in turbomachines such as gas turbines typically operate in high temperature environments. In order to efficiently cool the components, which may for example include nozzles, shrouds, and buckets, cooling passageways may be cast into the body of the components during fabrication. These cooling passageways allow a fluid to circulate through the cooling passageways, carrying energy in the form of heat away from the component.
The casting process for fabricating such components may result in the formation of components having holes in the walls of the cooling passageways. These holes may be sealed by, e.g., welding, brazing, threading, or other means, such as inserting a plug into or over the hole.
In embodiments in which the cooling passageways include features or geometries on an interior of the cooling passageway to increase heat transfer effectiveness and promote cooling, the plugged area of the cooling passageway wall typically lacks such cooling features. The plugged hole thus becomes a dead zone in the cooling circuit, and/or may interfere with the desired flow pattern for maximum cooling.